Production of Oil and Protein Food Products from Raw Peanuts by Aqueous Extraction and Ultrafiltration

Two significant protein isolation techniques (the Aqueous Extraction Process and the Membrane Isolation Process) were combined to obtain a new processing strategy for producing oil and protein food products from raw peanuts. Three varieties of peanuts were processed to obtain either a low-fat isolate or a full-fat product and an oil cream using aqueous extraction, centrifugation and industrial ultrafiltration membranes. Proximate and amino acid analyses and nitrogen solubility profiles were made on spray-dried products. Mean membrane permeation rates achieved exceeded 70 gallons per sq ft per day (gfd). Protein products possessed high nitrogen solubility, a bland taste, and were desirably light in color.     

Functional properties of plant proteins. Part 2. Selected physicochemical properties of native and denatured protein isolates from faba beans,soybeans, and sunflower seed

Functional properties — as solubility, water and oil adsorption, emulsifying capacity, emulsion activity and stability — of protein isolates from faba beans, soybeans and sunflower seed depending on the isolation process were determined. Proteins isolated under mild conditions, it means by precipitation using dialysis or dilution of salt extracts with water, show the highest solubility, characterized by a sharp minimum of solubility at a rather narrow range of pH. An incubation of the precipitated proteins at low pH (pH 2) results in a decrease of the solubility on the alcaline and acidic part of the solubility profile. On the contrary to the decreased solubility, the proteins denatured by acid show an increased water adsorption capacity. Depending on the kind of protein and the conditions of preparation these values can reach the manifold ones of the control. Smaller increases of oil adsorption in acid-denatured proteins were found, too. The emulsion activity and stability were not or only slightly influenced, but the emulsifying capacity was strongly decreased by the denaturation procedure. The emulsifying capacity was influenced by the solubility of the protein, but a strong correlation does not exist. The high water adsorption of Promine D can be reached by the other plant proteins after denaturation. The sunflower protein showed the highest emulsifying capacity. Increasing the pH from the isoelectric range to 7 improves all studied functional properties.     

2011年深圳转基因大豆及其制品的市场占有率和标识情况调查

目的 了解深圳市场转基因大豆及其制品的市场占有率和标识情况,为政府监管转基因大豆提供科学依据.方法 按照监测计划,定期在深圳市场随机抽取大豆及其制品,采用实时荧光PCR方法对其进行定性和定量检测,评估深圳市场转基因大豆的市场占有率和标识情况,并与2006年的监测结果进行比较和分析.结果 2011年共监测样品106份,检出2份转基因阳性样品,市场占有率为1.89％;两份阳性样品中转基因大豆的含量分别为0.93％和0.51％,定量检出限为0.1％.所有检出转基因阳性样品均没有转基因标识;与2006年结果比较,转基因大豆及其制品的市场占有率以及标识情况差异均无统计学意义.结论 目前深圳市场转基因大豆及其制品(食用油脂除外)的市场占有率还很低,并且5年来未发现明显上升;转基因产品标识的管理还有待加强,政府应该加大这方面的执法力度.     

Aqueous Extraction and Membrane Techniques Improve Coconut Protein Concentrate Functionality

Functional properties of coconut protein concentrates (CPC) from fresh coconut meat and commercial desiccated coconut meat were assessed and compared with other protein sources. Coconut proteins were extracted from undefatted meats at pH 7 in 0.5M NaCl solution. Protein recovery in the ultrafiltration retentates was about 40% (as % nitrogen) in the starting meats. Water absorption capacities of CPC products were lower than those of soy protein concentrates (SPC) and Na-caseinate, but there was no difference in oil absorption values among CPC, SPC and Na-caseinate. CPC products were more soluble than SPC, but less soluble than Na-caseinate at pH 8 and 10. Emulsifying properties of CPC were superior to those of caseinate and SPC. Total essential amino acids contents of CPC products were lower than caseinate, but similar to SPC.     

Extrusion of Pinto Bean High Protein Fraction Pretreated with Papain and Cellulase Enzymes

High protein fraction of pinto bean was pretreated with papain and cellulase enzymes and extruded at a temperature of 120°C. The effect of enzyme type and concentration, moisture and duration of incubation on expansion, texture, color, water absorption and solubility, pH, sugars, nitrogen solubility index and in vitro protein digestibility of the extrudate were investigated. Enzymatic modification had differential effects on nitrogen and carbohydrate components and on some physical and functional preperties of extrudates, depending on type of enzyme and incubation conditions. Results indicated the possibility of controlling protein and fiber hydrolysis at low moisture to obtain a desirable degree of modification to improve extruded products. This method may be used in food applications to obtain new snack type products from beans or their fractions.     

EFFECT OF FREEZE DAMAGE ON SOYBEAN QUALITY AND STORAGE STABILITY

In order to study the whole bean quality and storage stability of free-zedamaged soybeans, immature soybeans were frozen in their pods at -5.5°C for 6 hr. When compared to undamaged soybeans, freeze-damaged soybeans were found to have similar oil and protein contents and trypsin inhibitor activities, but lower lipoxygenase activity and greener oil color. The oil from freeze-damaged soybeans averaged 0.26% free fatty acid and increased to 1.63% during 14 months of whole bean storage; oil from undamaged soybeans averaged only 0.14% and increased to 0.48% during storage. Sensory evaluation of cooked soybeans showed that freeze damage increased off-flavors and resulted in poorer color.     

Textural Properties of Mozzarella Cheese Analogs Manufactured from Soybeans

Mozzarella cheese analogs were produced from soybeans or soy protein products, gelatin, gum arabic and other ingredients. The method for production of the cheese analog consisted of the following: (1) mixing at controlled temperatures to obtain a homogeneous mass, and (2) tempering at a temperature of 4°C for 24 hr. Several analog formulations were evaluated and the factors such as pH, fat content, salt content, influencing textural characteristics were studied with an Instron Universal testing machine and a modified Weissenberg test. The physical and functional properties of the final product were found to be similar to those of natural mozzarella cheese (low moisture part-skim) tested and evaluated with the same experimental methods.     

Feeding fish meal and extruded soybeans enhances the conjugated linoleic acid (CLA) content of milk

Twelve multiparous Holstein cows averaging 65 (33 to 122) DIM were used in a 4 x 4 Latin square for 4-wk periods to determine whether feeding fish oil as fish meal would stimulate increased amounts of milk conjugated linoleic acid (cis-9, trans-11 C18:2; CLA) and transvaccenic acid (trans-11 C18:1; TVA) when the cows were fed extruded soybeans to supply additional linoleic acid. Treatment diets were 1) control; 2) 0.5% fish oil from fish meal; 3) 2.5% soybean oil from extruded soybeans; and 4) 0.5% fish oil from fish meal and 2% soybean oil from extruded soybeans. Diets were formulated to contain 18% crude protein and were composed (dry basis) of 50% concentrate mix, 25% corn silage, and 25% alfalfa hay. Intake of DM was not affected by diet. Milk production was increased by diets 2, 3, and 4 compared with diet 1 (control). Milk fat and milk protein percentages decreased with diets 3 and 4. Milk fat yield was not affected by treatments, but yield of milk protein was increased with supplemental fish meal and extruded soybeans or their blend. When diets 2, 3, or 4 were fed, concentrations of cis-9, trans-11 CLA in milk fat increased by 0.4-, 1.4-, and 3.2-fold, and TVA concentrations in milk fat increased by 0.4-, 1.8-, and 3.5-fold compared with the control milk fat. Increases in TVA and cis-9, trans-11 CLA were 91 to 109% greater when a blend of fish meal and extruded soybeans was fed than the additive effect of fish meal and extruded soybeans. This suggested that fish oil increased the production of CLA and TVA from other dietary sources of linoleic acid such as extruded soybeans.     

EFFECT OF PROCESSING METHOD AND pH OF PRECIPITATION ON THE YIELDS AND FUNCTIONAL PROPERTIES OF PROTEIN ISOLATES FROM GLANDLESS COTTONSEED

SUMMARY— Glandless cottonseed meals were prepared under controlled conditions in a pilot plant by three different processing methods. These meals along with a glandless cottonseed meal produced at a commercial oil mill were used as source meals for protein isolates. Two protein fractions differing in composition and characteristics were isolated from each type meal using a two-step, two-solvent isolation procedure developed at the USDA Southern Utilization R & D Div. yields of each isolate precipitated at three different pH levels were determined on the pilot plant meals. Isolate yields from the commercial meal were determined near the respective isoelectric points of the two fractions. Functional properties including whippability, heat gelation, solubility and foaming properties, were measured on all isolates. Variation in measured values due to meal processing method and precipitation pH was statistically assessed in some instances. Meal processing method was found to significantly affect the yield of Isolate I, the minor isolate. pH of precipitation was found to significantly affect the yield of Isolate II, the major isolate. Also, it was shown that the pH-solubility profiles of both Isolates I and II could be altered by changing the pH at which they were precipitated. The functional properties of isolates from meals processed without heat were superior to those of isolates from heated meals. Data collected indicated the need for a new practice in evaluating the extent of denaturation of cottonseed protein products. The present practice of determining nitrogen solubility at one point was shown to be inadequate.     

双酶分步水解制备花生多肽工艺优化

为了开发和利用花生蛋白资源,生产高附加值蛋白产品,以花生分离蛋白为原料,采用Alcalase 和Flavourzyme 分步水解法制备花生多肽。通过单因素试验和响应面中心组合设计试验,研究Flavourzyme 水解花生分离蛋白过程中加酶量、底物质量分数、酶解温度、酶解时间和酶液pH 值等因素对水解的影响。建立水解液中可溶性氮质量浓度与各种影响因素的回归模型;确定Flavourzyme 酶解反应的最佳工艺参数为pH7.0、加酶量1714U/g 底物、底物质量分数5%、酶解温度55℃、酶解时间90min。在此条件下,酶解产物中可溶性氮质量浓度为19.44mg/mL。     

正交试验优化传统腐竹制作工艺

采用物性测定仪及色差仪法结合产品的出品率等指标,对影响腐竹得率和品质的工艺条件进行研究,确 定最佳的腐竹生产工艺流程。单因素试验和正交试验结果表明,影响腐竹得率和品质的因素分别为：浆液pH值、 脂肪/蛋白质比率,糖类/蛋白质比率,揭膜温度、打浆豆水比。对影响揭膜过程的工艺条件进行正交试验,最终确 定腐竹标准工艺条件为原料大豆蛋白质含量34.42%、脂肪17.52%、总糖15.77%、水分11.91%、揭膜浆液pH 8.0、 脂肪/蛋白质0.2、糖类/蛋白质0.3、揭膜温度85 ℃、打浆豆水比1∶7。此时腐竹得率为49.02%（对干豆）,明度 49.72,抗拉强度3.46 MPa,延伸率11.18%,腐竹水分含量9.12%,蛋白质含量46.89%,脂肪含量26.09%,总糖含量 12.09%,各项指标符合相关标准。实验所得腐竹与文献报道结果相比,在得率和明度基本保持不变的情况下,抗拉 强度提高18.60%,延伸率提高6.93%。     

Effect of different denaturating methods on lipid-protein complex formation

To investigate the effect of denaturation of protein on lipid-protein complex formation in soybeans, different denaturing agents including urea, ethanol, autoclaving, and extreme pH treatment were used. Protein was denatured either in the presence of the oxidized crude soybean oil (MO_x OD), or before it was added to the crude oxidized oil (DMO_xO). Nitrogen solubility index and in vitro digestibility of the proteins were used to investigate the formation of the lipid-protein complexes. The meal resulting after the denaturation treatment was compared to untreated soybean meal. All treatments resulted in very highly significant differences (P>0.001) in the studied parameters when compared to untreated meal. Results proved that denaturation of protein in the presence of oxidized oil caused more lipid-protein complex formation than denaturation of the protein prior to the addition to the oxidized oil. Among the denaturing agents examined, urea caused the highest lipid-protein complex as indicated by the in vitro digestibility and nitrogen solubility of the protein.     

脱皮大豆等温吸水模型与复水磨浆工艺参数优化

目的:探讨脱皮大豆复水磨浆工艺参数对钝化大豆脂肪氧化酶及蛋白得率的影响,为高品质豆奶产品的研制提供理论与技术支持。方法:通过构建脱皮大豆的等温吸水模型来探讨吸水率与大豆蛋白得率的关系;以浸泡液温度、pH及浸泡时间为因子,大豆蛋白得率及脂肪氧化酶活性钝化指数为指标,优化脱皮大豆磨浆吸水工艺参数。结果与结论:脱皮大豆的等温吸水模型符合M=115.693-e-(at2+bt+c),a、b、c为与温度有关的常数,磨浆大豆的复水吸水率达到90%以上时,大豆蛋白提取利用趋于最大值。影响大豆蛋白质得率的主次顺序为浸泡时间 > 浸泡温度 > 浸泡液pH,影响钝化脂肪氧化酶活性的主次顺序为浸泡温度 > 浸泡液pH > 浸泡时间,综合考虑脂肪氧化酶活性钝化及蛋白得率,选优处理组合为浸泡液温度80 ℃、pH9,浸泡时间60 min,蛋白质得率可达90.76%,脂肪氧化酶活性钝化指数达92.78,脱去豆腥味效果显著。     

Structural and Functional Properties of Hemp Seed Protein Products

The effects of pH and protein concentration on some structural and functional properties of hemp seed protein isolate (HPI, 84.15% protein content) and defatted hemp seed protein meal (HPM, 44.32% protein content) were determined. The HPI had minimum protein solubility (PS) at pH 4.0, which increased as pH was decreased or increased. In contrast, the HPM had minimum PS at pH 3.0, which increased at higher pH values. Gel electrophoresis showed that some of the high molecular weight proteins (>45 kDa) present in HPM were not well extracted by the alkali and were absent or present in low ratio in the HPI polypeptide profile. The amino acid composition showed that the isolation process increased the Arg/Lys ratio of HPI (5.52%) when compared to HPM (3.35%). Intrinsic fluorescence and circular dichroism data indicate that the HPI proteins had a well‐defined structure at pH 3.0, which was lost as pH value increased. The differences in structural conformation of HPI at different pH values were reflected as better foaming capacity at pH 3.0 when compared to pH 5.0, 7.0, and 9.0. At 10 and 25 mg/mL protein concentrations, emulsions formed by the HPM had smaller oil droplet sizes (higher quality), when compared to the HPI‐formed emulsions. In contrast at 50 mg/mL protein concentration, the HPI‐formed emulsions had smaller oil droplet sizes (except at pH 3.0). We conclude that the functional properties of hemp seed protein products are dependent on structural conformations as well as protein concentration and pH.     

Functional Characteristics of Protein Flaxseed Concentrate Obtained Applying a Response Surface Methodology

ABSTRACT:  Food preferences by human beings are based on sensory attributes such as texture, flavor, color, and appearance that depend mainly on the interactions between minor and major components of the food. Some functional properties depend directly on the proteins, such as oil and water absorptions, foam and emulsion activities, and viscosity. The objective of this work was to obtain and evaluate the functional properties of flaxseed protein concentrate. Flaxseed was ground, defatted, and sieved to eliminate hull fiber. Surface response methodology with 5 central points and 4 axial points was used to determine how to obtain the highest protein concentrate. The independent variables used were solubilization pH (which varied from 9 to 11) and precipitation pH (which varied from 4.2 to 4.8). Treatment with a solubilization pH of 11 and a pH extraction of 4.8 gave 66.03% protein content. The flaxseed protein concentrate contained 2.56% fat, 6.62% ash, 2.44% insoluble fiber, 15.79% soluble fiber, and 6.59% sugars. The product had oil and water absorption capacities of 150.25% and 253.5%, respectively. Better foam stability (83.33%), emulsifying capacity (84.76 mL/g), and emulsifying activity (88.37%) of the flaxseed protein concentrate were observed at a pH 6. In light of its functional properties as indicated by this study, flaxseed protein concentrate may be recommended for use as an ingredient in products such as meat batters, hamburgers, and ice cream.     

中国大豆工业当前形势及展望

叙述了中国大豆资源情况。由于国内需求的迅速增长 ,必须扩大大豆种植面积和提高产量 ,并且增加国外进口数量。中国传统大豆制品业历史悠久 ,大豆工业经过 5 0多年的发展已具一定规模 ,文章对中国大豆工业的现状进行了叙述。预计未来 5年 ,中国大豆加工量将迅速增长 ;大豆油厂的规模和布局将逐渐趋于合理 ;将更加注重大豆蛋白产品的功能特性 ,积极采用功能特性修饰技术 ,开发出更多种类的功能性、专用性大豆蛋白产品 ;同时将更加注重大豆资源的综合利用 ,在制油和生产大豆蛋白产品的同时 ,从大豆所含植物化学成分中开发出附加值更高的新产品。     

Effects of Microwave Heating on Solubility, Digestibility and Metabolism of Soy Protein

Microwave heating of soybeans for 9 min decreased protein solubility from 80 to 17%, from 81 to 18%, and from 72 to 16% when deionized H2O, 0.6N NaCl and 0.4N CaCl2, were used as solvents, respectively. Experiments were conducted to determine ‘in vivo protein digestibility and metabolizable nitrogen using male Sprague-Dawley rats. The percentages of true digestibility were found to be 73, 84, 87 and 81 when the soybeans were microwave heated for 0, 9, 12 and 15 min, respectively. Microwave heating soybeans up to 15 min did not alter the fatty acids composition of the beans.     

Effect of Soybean Maturity on Storage Stability and Process Quality

Hack and Williams 82 soybeans from four maturation stages were studied for storage stability and process quality. As compared to mature beans, trypsin inhibitor, urease and lipoxygenase (LA) activities were lower in immature seeds, but free fatty acid (FFA) was higher and oil was greener. During storage for six months, LA decreased and FFA increased at a faster rate in immature than in mature soybeans. Crude oil and protein contents were similar, regardless of maturation or storage time. Both 7S and US proteins increased with maturation but the 7S/11S ratio decreased. There was no change in protein during storage.     

Extruded Soybeans and Corn Gluten Meal as Supplemental Protein Sources for Lactating Dairy Cattle

Holstein cows in early lactation were used to compare three combinations of extruded whole soybeans and corn gluten meal to soybean meal. Treatments were (as a percentage of supplemental crude protein) 100% soybean meal; 75% whole soybeans extruded at 149°C, 25% corn gluten meal; 50% extruded soybeans, 50% corn gluten meal; and 25% extruded soybeans, 75% corn gluten meal. Diets were formulated to be 37.5% corn silage, 12.5% alfalfa cubes, and 50% concentrate (dry matter). Dietary crude protein was 15.7% of dry matter, and supplemental protein sources supplied 27% of total dietary protein. Diets were fed as total mixed rations and data were collected from 4 to 116 d postpartum.Milk and fat-corrected milk yields ranged from 31.0 to 34.3 and from 29.3 to 33.3 kg/d, respectively, and were greater for cows fed soybean meal than those cows fed 75 or 50% of their supplemental protein as extruded soybeans. Milk yield of cows consuming 75% of their supplemental protein from corn gluten meal was similar to all other treatments. Ruminal ammonia concentrations were lower in cows fed extruded soybeans and corn gluten meal compared with those fed soybean meal and ranged from 9.1 to 12.4mg/100 ml. Total volatile fatty acid concentration and pH did not differ among treatments. Combinations of extruded soybeans and corn gluten meal were not advantageous compared with soybean meal as a supplemental protein source for lactating cows in this experiment.     

Co-processing Soy Proteins and Milk Proteins with Commercial Ultrafiltration Membranes

Ultrafiltration (UF) membranes were used to co-process soy protein extract and skim milk seeking to produce soy-milk food ingredients with protein efficiency ratios (PERs) of 2.5 or higher. Extracts from two commercial soy flours and ground soybeans were blended with commercial skim milk before and after ultrafiltration. Protein blends of 67% soy-33% milk, 50% soy-50% milk and 33% soy-67% milk were processed. Soy-milk products possessed high nitrogen solubility and light color. Lysine contents of soy-milk products ranged from 7.34–6.82%. PERs ranged from 2.36 for 33% soy-67% milk to 1.47 for UF soy isolate without milk. Soy and milk proteins exhibited some synergistic effects, but none of the soy-milk PERs reached the 2.5 level.